1. Field of the Invention
This invention relates to thin film deposits of iron-silicon. It also relates to low coercivity material for magnetic recording thin film heads, and this invention relates as well to metal working and, more particularly, to processes of mechanical manufacture of a magnetic transducer for use in magnetic recording.
2. Description of the Prior Art
U.S. Pat. No. 3,605,258 of Fisher et al shows a sputtering system for depositing a nonmagnetic material such as glass upon a portion of a bar of magnetic material upon the surface to provide a magnetic gap. Permalloy is later sputtered onto another portion of the bar with use of photoresist masks to control where the deposits are made.
K. Y. Ahn, "Magnetic Film for an Integrated Recording Head," IBM Technical Disclosure Bulletin, Vol. 13, No. 5, October 1970, p. 1185 describes deposition of iron-silicon films upon silicon wafers heated to 200.degree. C. by simultaneous evaporation of Si and Fe using two electron beams guns with a typical evaporation rate of 20-30 Angstrons/sec. Pressure was from 10.sup.-.sup.5 Torr to 6 .times. 10.sup.-.sup.6 Torr. Silicon was 5-15% by weight in the resulting film. No low coercivity films were reported there and such techniques do not yield low coercivity film. The range of Si content is too large and the substrate temperature is far too low to produce proper thermal stresses.
I. Pockrand and J. Verweel, "Magnetic Domains in Thin Films I," Phys. Stat. Sol. (a) 27, 413 (1975) describe effects of argon sputtering gas pressure upon Fe - 5.8% Si for potential use in an integrated circuit memory with a coercivity of 11.3 Oe at 1.8 .times. 10.sup.-.sup.3 Torr, which is unacceptably high and 1.3 Oe at 21 .times. 10.sup.3 Torr which is better.